Effects of Solid-State Phase Transformation on the Evolution of Welding Residual Stresses in Medium Carbon Steel Pipes

In the pressent study, the effect of the solid-state phase transformation on the evolution of residual stresses in circumferentially butt-welded medium carbon steel pipes is survied using an effective algorithme. For this purpose a thermoelastic- plastic analysis coupled with metallurgical analysis using finite element method is implemented. Welding process is simulated in 2-D and 3-D using two subroutines: one for applying heat flux and the other to consider the effect of phase transformation due to austenite-martensite transformation. The simulation results show that austenite-martensite transformation has significant effects on magnitude and distribution of residual stresses, and in some cases, it changes its nature from tensile to compressive stresses.